Optical image measuring apparatus

An optical image measuring apparatus, comprising:

• a light source for emitting a light beam;
• a first beam splitter for dividing the light beam from the light source into signal light reflected by an object to be measured in a plurality of depth regions, and reference light reflected by a predetermined reference object;
• a second beam splitter for dividing the reference light into a plurality of reference light beams;
• a plurality of frequency shifters arranged on optical paths for the plurality of reference light beams divided by the second beam splitter and adapted to shift frequencies of the plurality of reference light beams by different amounts;
• a plurality of reflector plates as the reference objects arranged on the optical paths for the plurality of reference light beams and at difference distances from the object to be measured;
• a third beam splitter for superimposing the plurality of reference light beams whose frequencies are shifted by the frequency shifters and which are reflected by the reflector plates on the signal light reflected by the object to be measured in the plurality of depth regions to produce interference light including a plurality of interference light components whose frequencies are different depending on the depth region thereof;
• and
• a shutter for cutting off the produced interference light with a frequency synchronous with any one of shift amounts of the frequencies to extract the interference light component corresponding to the synchronous frequency from the interference light;
• a CCD camera for receiving the extracted interference light component and converting the extracted interference light component into an electrical signal to output the signal;
• and
• a computer for calculating an intensity of the interference light component and a phase distribution based on the outputted electrical signal, and calculating a reflectance distribution of the object to be measured in the depth region corresponding to the interference light component based on the intensity and the phase distribution, to form the image based on the reflectance distribution.